Select all the systems of equations that have exactly one solution. y = 3x + 1 y = -3x + 7 y = 3x + 1, , y = -3x + 7, y = 3x + 1 y = x + 1 y = 3x + 1, , y = x + 1, y = 3x + 1 y = 3x + 7 y = 3x + 1, , y = 3x + 7, x + y = 10 2x + 2y = 20 x + y = 10 , , 2x + 2y = 20 , x + y = 10 x + y = 12

Step-by-step explanation:

2 is the final ! : )

if gloria has "carry over" minutes, (that is, any minutes paid for but not used in a month can be applied to her payment for minutes in the next month,) her total usage for the three months is: total minutes = 320 + 243 + 489 = 1052 minutes number of 200 minute blocks = 1052/200 = 5 r52 (that is 5 with a remainder of 52) rounding up the number of 200 minute blocks gives her usage for the three months as 6 blocks. the cost for six blocks is 6 x $25 = $150 she also has 200 - 52 or 148 carry over minutes if gloria pays each month and unused minutes are lost, applying the rounding up procedure to each month gives: first month usage of 320 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 second month usage of 243 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 third month usage of 489 minutes rounds up to 3 blocks of 200 minutes for a payment of 3 x $25 = $75 total payments for the three months are $50 + $50 + $75 = $175 get the plan with carry over minutes!